Dendritic polymers, particularly polyamidoamines and amidoalcohols, polyethers, polythioethers, polyethyleneimines and polyamides are described in Encyclopaedia of Polymer Science and Engineering, index volume, 1990, John Wiley & Sons, New York in an article by D. A. Tomalia et al. at pages 46-92. Dendritic polyesters are described in WO-A-93/18075. U.S. Pat. No. 5,229,490 describes dendritic polyamides having antigens bound thereto.
The spherical nature of dendrimers leads to high molecular weight molecules which do not suffer from entanglement, unlike conventional linear chain polymers. Dissolution in solvents is therefore fast and viscosities are low, leading to the possibility of "high solids" formulations, for example of coatings, sealants or adhesives, with favourable physical properties. The crosslinking of dendrimers leads to the formation of highly branched networks even after very few reactions have occurred, and the subsequent increase in molecular weight is dramatic, leading initially to linear-like entangled networks and then to highly crosslinked materials.
There is a need for dendrimers based on a wider range of chemical linkages and for alternative methods of preparation of dendrimers.
Functionally tipped polymers are known; for example hydroxyl and amino tipped polyethers, amino tipped polyamides and carboxyl tipped diene polymers are available commercially. There is a need for polymers tipped with a plurality of functional groups at each end and for convenient reactions for changing the terminal functionality of a polymer.
A paper by F. M. Houlihan et. al. in Macromolecules 1986, 19, pp 13-19, describes the synthesis of linear tertiary polycarbonates by reacting a ditertiary alcohol with carbonyl diimidazole and reacting the product with a diprimary alcohol.